Two-micrometer-thick Pb0.97La0.02(Zr0.98Ti0.02)O3 (PLZT) antiferroelectric films, with the addition of different PbO insert layer, were successfully fabricated on LaNiO3/Si substrates through a sol–gel method, and their microstructure and the energy storage performance were investigated in detail. X-ray diffraction curves and scanning electron microscopy images indicated that all the PLZT films showed a strong (042)-preferred orientation and had a uniform surface microstructure. The electrical measurements illustrated that the capacitive density and saturation polarization values of the thick films were improved by the PbO insert layer. As a result, PLZT thick films with 0.4‐M/L PbO‐insert layer possessed an enhanced energy storage density and energy storage efficiency, which were 25.2 J/cm3 and 52.3% measured at 984 kV/cm, respectively. Moreover, after 106 switching, the Jreco values of the corresponding films were only declined from 17.5 to 16.1 J/cm3, indicating good fatigue endurance.